Nucleic acid isolation using magnetic particles, invented by T. Hawkins in 1998 [18], has demonstrated great results in yield, cost-effectiveness, scalability, and ease of use and automation compared to many other methods. The lack of centrifugation or other potentially damaging processes helps to preserve the structure of the nucleic acids. The procedure for extracting nucleic acids with this method is extremely user-friendly, requiring only inexpensive and straightforward laboratory equipment. [1, 19, 20]

This method of nucleic acid extraction uses magnetic properties of nucleic acids and certain binding compounds. These compounds may consist of iron, zinc or nickel oxide beads or magnetizable cellulose particles. After breaking the cell wall and adjusting the salt and polyalkylene glycol concentrations, negatively charged DNA and RNA molecules attach to positively charged magnetic beads. A magnet can then be placed on the side of the container, pulling the magnetic particles with already bound nucleic acids. After magnetization the remainder can be easily washed away with a buffer solution. [12, 18, 19]

Various coatings can be used to prepare magnetic particles depending on the type of sample and the desired outcome of the extraction. For example, iron oxide beads can be prepared using silane and carboxyl compounds, which aid in binding nucleic acids in polyethylene glycol solutions [18]. Alternatively, the beads can be coated with biopolymers like agarose, chitosan, κ-carrageenan, or alginate. Uncoated iron oxide molecules, however, tend to clump together, reducing the surface area available for nucleic acid binding. There are numerous other bead modification methods, each offering unique benefits and applications. [19]